Casio appears to be preparing a major new addition to its rugged watch lineup that draws heavy visual inspiration from one of high-end horology's most iconic silhouettes. Following the massive success of the GA-2100 series, which watch enthusiasts affectionately dubbed the CasiOak for its resemblance to the Audemars Piguet Royal Oak, leaks have surfaced showing an upcoming set of all-analog models with prominent case ears reminiscent of the Patek Philippe Nautilus. Informally christened the CasioNaut or CasioTilus across enthusiast channels, the new lineup consists of the resin-framed GAC-2500 and the stainless steel GMC-2500.
A Design Legacy Rooted in Luxury Horology
In 1972, legendary watch designer Gérald Genta introduced an angular stainless steel timekeeper to Audemars Piguet, pairing a high-end movement with a steel case priced higher than traditional gold dress watches. That creation, the Royal Oak, birthed the luxury sports watch category. Just four years later in 1976, Genta adapted a similar design philosophy for Audemars Piguet's prime competitor, Patek Philippe, creating the Nautilus. Lore has it that Genta drew inspiration from transatlantic ocean liner portholes, sketching the iconic watch in just five minutes at a hotel restaurant while observing Patek executives across the room.
Casio previously tapped into this high-low luxury design appeal in 2019 with the launch of the wallet-friendly GA-2100. Its octagonal bezel offered consumers an accessible taste of high-end aesthetics, a strategy Swatch recently echoed with its Royal Pop release. The new CasioNaut project builds directly on that legacy while pulling design cues from Patek Philippe's famous porthole case silhouette.
Specs, Materials, and Model Variants
The forthcoming GAC-2500 series features a resin construction built on the fundamental engineering DNA of the original 1983 DW-5000C, the very first G-Shock ever produced. For buyers looking for a premium metal finish, Casio is offering the GMC-2500 lineup in stainless steel. Initial information suggests that four resin colorways will launch: white, black, green, and yellow. The metal GMC-2500 variants are expected to provide various dial colorways along with options for both integrated metal bracelets and rubber straps.
In terms of physical footprint, the stainless steel GMC-2500 measures 46.7 mm long by 43.8 mm wide and 12.9 mm thick. The resin GAC-2500 comes in slightly broader but marginally slimmer, measuring 46.7 mm by 44.5 mm by 12.7 mm.
All-Analog Dial and Shock-Resistant Engineering
One of the most notable features of the CasioNaut lineup is its completely analog display. Unlike most primary G-Shock models, including the CasiOak which incorporates a small digital LCD window alongside analog hands, these new models omit digital screens entirely.
The dial layout utilizes a two-eye format featuring a small running seconds subdial positioned on the left side and a classic date window on the right side. The tail of the central seconds hand bears a subtle Shock Resist branding mark. Beneath the dial, these timepieces incorporate Casio's specialized Magnetic Holding Structure. Rather than mounting the watch hands permanently on a rigid central shaft, this mechanism secures them using magnetic force. When the watch receives a heavy impact or drop, the hands detach momentarily to absorb the kinetic shock before snapping back into place, preventing axis breakage or internal mechanical damage.
Expected Pricing and Launch Window
The resin-cased GAC-2500 models are anticipated to carry a retail price tag of 20,900 Japanese yen, which translates to approximately $134. Meanwhile, the stainless steel GMC-2500 models are expected to sit at a higher price tier of around $320. All four resin variants and their metal counterparts are slated for an official release window in November.
